SPORTPLANE BUILDER

Tony Bingelis

Part 2 Last month I covered in some detail the preparation of my new Lycoming engine for installation. Hanging the engine on its dynafocal mounts was quite successful in that we did not drop the engine. A forecasted, but unexpected, rain shower didn't help speed the installation nor did it deter us from getting all four engine bolts inserted, torqued, and safetied. (The "we" and "us" I refer to includes one very talented fellow RV-6A builder.) With the engine safely hung, there was no longer a need for that tree branch hoist set up. Anyway, I had my friend climb up on a stand (I'm afraid of ladder heights) and take that thing down as soon as possible because it looked more like a lynch scene than a respectable shade tree operation. After trundling the fuselage with its newly acquired engine back into the garage - a garage that has never known the presence of an automobile in 20 years - I immediately went to work installing the various accessories and support systems the engine needed to be operational. A few of these were detailed last month. Thus far the work accomplished included: 1. The essential, but simple, procedure for modifying the hollow crankshaft so I could use a fixed pitch propeller. 2. The installation of a restrictor fitting in the oil pressure port located next to the upper right dynafocal mount. 3. The installation of the engine ground strap (cable). 4. A discussion of the gascolator, its function in a low wing aircraft, and a simple design for making a cooling shroud. That brings us up to date. I'm sure by now you realize that installing a new engine in a new airplane will be more difficult and take much longer than replacing an engine in an operational aircraft. This is because in a new installation, not only do you have to determine exactly where to puncture the firewall for the engine controls, you also have to figure out where to mount the accessories, how to route the fuel and oil lines, and all the elec84 MARCH 1992

This exhaust slip joint is held together by two strong springs

auto racing style. Very effective.

trical stuff. Fortunately, there is no particular sequence for installing any of the systems and controls. However, logic will tell you that some things have to be done before others. For example, you should make and

install the engine baffles before you attempt to install the oil cooler. Otherwise, where and how would you mount it? (See SPORT AVIATION October and November 1986, Baffling Your Lycoming, for baffle patterns.)

Long exhaust tail pipes must be supported. However, this support strap (A) won't last long because it is anchored to the unyielding firewall while the exhaust pipe moves with the shock mounted engine.

18 GAGE WIRE TO INSTRUMENT ALUMINUM 5/16" i 2 l«" « I V4" LIGHTEN AS SHOWN.

OIL PRESSURE SENDER ^TYPICAL)

CLAMPING BOLT (AN3) COUPLING AN9IO-ID OR AUTO PARTS STORE (1/8 PIPE THREAD).

AN823-2 OR2D MODIFIED INTO RESTRCTOR FITTING.

AEROQUIP 303-3 HOSE

expensive unit. Treat it with care. As you may recall, my engine was shipped with the carburetor removed and packed in its own cardboard box. Since it was pickled (preserved) at the factory, it, too, had to be prepared for service before attaching it to the engine. This merely entailed the removal of the fuel drain plug, and draining the preservative oil. (Mine didn't have any.) Lycoming also recommends that the fuel inlet strainer be removed and cleaned in a hydrocarbon solvent, like naptha, before installing the carburetor on the engine (yes, Wilbur, I know it actually goes under the engine). Don't forget to reinstall the fuel drain plug and fuel inlet strainer assembly. Fuel and Oil Line Connections

ALUMINUM BRACKETS .050

FUEL PRESSURE SENDER

CLAMP TO SENDER HOUSING

(TYPICAL)

STAINLESS STEEL HOSE CLAMP

FIGURE I. MOUNTING FUEL/OIL PRESSURE SENDERS

Here's another example. Remem-ber to install the alternator pulley belt before you mount the propeller and prop spinner (no, Wilbur, you cannot cut and splice the belt, later, to get it on ... duct tape is good but it won't hold). Get the idea? Now that you are alerted, be prepared for similar traps. However, in spite of your best efforts, you will find yourself removing and replacing some hook-ups more than once before you get them just the way they should be. Removing the Engine From Storage

Since a new engine is prepared for storage by the factor prior to shipment, it must be removed from that storage status before operating it. The most important need is to drain the preservative oil before turning the crankshaft. If you fail to do this you may damage the engine because the liquid (preservative oil) does not com-

press. The risk is especially high if an appreciable amount of the preservative is trapped in the cylinders. This can result in an unyielding hydraulic block (hydraulicin). So ... 1. Drain the preservative oil from the cylinders by removing the bottom spark plugs and turning the crankshaft a few revolutions. 2. Remove the oil sump plug and drain whatever preservative oil is in the sump. Resafety the plug and fill the crankcase with fresh mineral oil. (I will use straight mineral oil until my oil consumption has dropped noticeably or has stabilized. This may take up to

As a former dedicated cheapskate, I know how tempting it is to install used (or old surplus) fuel and oil hoses . . . or at best trying to fabricate new ones with old reusable fittings, but without the benefit of the proper assembly tools. However, I have seen the light, and now firmly believe each new airplane should start its flying career with new fuel and oil hoses, properly fabricated. Furthermore, I believe those hoses should be pressure checked to at least system pressure. Engine oil pressure in a Lycoming can hit 100 psi. Recently, one of our gents completed a very successful forced landing after an oil cooler hose separated and pumped all the oil overboard. Unfortunately, the engine was not shut down soon enough to save it from a major overhaul. Since that incident, most of us around here have wondered about the condition of our own fuel and oil hose installations. Coping With Pressure Senders

Carburetor Installation

Most builders abhor the idea of piping fuel or hot oil into the cockpit area just to operate the fuel and oil pressure gages. I agree with that majority and strongly believe the oil pressure gage, and fuel pressure gage, should be electrical units activated by remotely located pressure senders. True, you do have to have an electrical system, and the installation is a bit more complex . .. but it is also safer. A pressure sender is normally con-

That new carburetor, a MarvelSchebler/Facet MA-4SPA, is a very

nected, by means of an aircraft quality hose, to the pressure source (fuel or oil) you want to monitor. As described

40-50 hours.)

Next, rotate the crankshaft a few turns to help lubricate the engine's interior and you will be ready for the next chore.

SPORT AVIATION R